Submitted to: Avian Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 5, 2005
Publication Date: June 20, 2006
Citation: Genovese, K.J., He, H., Lowry, V.K., Swaggerty, C.L., Kogut, M.H. 2006. Comparison of heterophil functions of modern commercial and wild-type Rio Grande turkeys. Avian Pathology. 35:217-223. Interpretive Summary: Many problems with food-borne pathogens such as Salmonella and other pathogens in commercially produced turkeys may be related to their inability to mount an efficient immune defense early in life. These studies compared the functions of white blood cells from commercial and wild-type turkeys. The wild turkey white blood cells were significantly better at defending the turkey against infections for the first two weeks after hatching than were the white blood cells of commercial turkeys. It is hoped that through further studies and comparisons of the immune systems of commercial and wild-type turkeys that genetic markers for immune efficiency can be identified and be utilized to develop a commercial line of turkeys that are more resistant to pathogens like Salmonella.
Technical Abstract: The purpose of the present study was to compare the functional differences in peripheral blood heterophils isolated from a commercial turkey line to wild-type Rio Grande turkeys. The phagocytosis of Salmonella, oxidative burst [production of reactive oxygen species;(OXB)] and degranulation [release of bactericidal compounds from granules within the cell;(DGR)], were used as parameters of heterophil functional efficiency in these studies. Blood was collected and heterophils isolated from each line of turkeys at days 4, 7, and 14 post-hatch. On days 4 and 7 post-hatch, heterophils from Rio Grande turkeys (RG) responded to PMA with significantly greater OXB activity than commercial line A. Results from the DGR assay also revealed a greater level of activity in RG heterophils when compared to heterophils from Line A turkeys. On day 14 post-hatch, heterophils from the commercial line A responded to stimulation with similar levels of degranulation (µM 4-methylumbelliferone) and the production of an oxidative burst compared to Rio Grande turkey heterophils. No differences in the phagocytosis of SE were observed between the lines. These results indicate that the commercial Line A turkeys may be at an immunological disadvantage during the first days post-hatch when compared to their wild-type predecessors. Results indicate that commercial line A turkeys have the ability to phagocytize bacteria, but are unable to effectively kill the bacteria once they are phagocytized. Exploiting the differences between the innate immune response of commercial and wild-type turkeys may help improve the immune system of commercial lines and decrease losses due to disease and decrease pathogen contamination of turkey products while preserving performance characteristics.